Good news, bad news for Alzheimer's research

Researchers deliver a mixed bag of news on their Alzheimer's work in this week's edition of the British medical journal The Lancet. One study yielded promising results while another sent some researchers back to square one.

Neurologists at Baylor College of Medicine in Houston analyzed the outcome of a Russian trial of the drug dimebon, an antihistamine previously untested on Alzheimer's patients. They discovered that, of 183 participants, those taking the drug noticeably improved in cognitive function compared to those who were given a placebo. On average, dimebon helped Alzheimer's patients score 6.9 points higher on the ADAS-cog test. Contingent upon further study, researchers believe this drug could be a useful supplement for current Alzheimer's medications such as Aricept and Namenda.

A blow to conventional wisdom, however, came from the Memory Assessment and Research Centre at Moorgreen Hospital in England. A vaccine designed to clear amyloid-beta plaques-a physiological hallmark of Alzheimer'sd isease-from the brain did not, as researchers had hoped, reverse or even slow the progression of the disease.

The experimental vaccine AN1792 performed its duty and removed the plaques, but there was no cognitive benefit for those receiving the drug. And while researchers still believe that preventing the plaques from building up in the first place will help treat early stages of dementia, they say removing them from the brain in established cases of Alzheimer's using this technique is an ineffective treatment.